The Great Lakes Water Quality Agreement of 1978 amended and strengthened the International Great Lakes Water Quality Agreement between Canada and the United States, which was signed in 1972. The original agreement established a framework for research, clean-up, and pollution control based on goals determined by the two nations. The existing International Joint Commission, in cooperation with the newly-created International Great Lakes Water Quality Board, was to oversee the implementation of the agreement. Chief goals of the agreement were to reduce the amount of phosphorus being dumped into the lakes by 50 percent, to require all municipal sewage treatment plants to be at the secondary level (removing nutrients such as phosphorous and nitrogen), and to control toxic water pollution.

The impetus for action in 1972, and again in 1978, was the decreasing water quality in the Great Lakes. Two incidents best symbolized this to the...